Quantitative fluorescent polymerase chain reaction for rapid prenatal diagnosis of fetal aneuploidies in chorionic villus sampling in a single institution

Abstract

ObjectiveTo validate quantitative fluorescent polymerase chain reaction (QF-PCR) via chorionic villus sampling (CVS) for the diagnosis of fetal aneuploidies.MethodsWe retrospectively reviewed the medical records of consecutive pregnant women who had undergone CVS at Cheil General Hospital between December 2009 and June 2014. Only cases with reported QF-PCR before long-term culture (LTC) for conventional cytogenetic analysis were included, and the results of these two methods were compared.ResultsA total of 383 pregnant women underwent QF-PCR and LTC via CVS during the study period and 403 CVS specimens were collected. The indications of CVS were as follows: abnormal first-trimester ultrasonographic findings, including increased fetal nuchal translucency (85.1%), advanced maternal age (6.8%), previous history of fetal anomalies (4.2%), and positive dual test results for trisomy 21 (3.9%). The results of QF-PCR via CVS were as follows: 76 (18.9%) cases were identified as trisomy 21 (36 cases), 18 (33 cases), or 13 (seven cases), and 4 (1.0%) cases were suspected to be mosaicism. All results of common autosomal trisomies by QF-PCR were consistent with those of LTC and there were no false-positive findings. Four cases suspected as mosaicism in QF-PCR were confirmed as non-mosaic trisomies of trisomy 21 (one case) or trisomy 18 (three cases) in LTC.ConclusionQF-PCR via CVS has the advantage of rapid prenatal screening at an earlier stage of pregnancy for common chromosomal trisomies and thus can reduce the anxiety of parents. In particular, it can be helpful for pregnant women with increased fetal nuchal translucency or abnormal first-trimester ultrasonographic findings.

Prenatal Diagnosis of Fetuses with Increased Nuchal Translucency by Genome Sequencing Analysis

“…Of noted, in routine setting, QF-PCR experiment was conducted prior to CMA for the detection of MCC and common aneuploidy. However, the missed detection of decreased copy-ratio of the Y chromosome by QF-PCR in this case might be due to the low level mosaicism presented (Shin et al, 2016). In addition, GS was able to delineate the 16p11.2 recurrent deletion which included the disease-causing gene TBX6 , missed detection of which in this customized CMA platform was owing to the lack of probes located in the target region (Figure 4B).…”

Prenatal Diagnosis of Fetuses With Increased Nuchal Translucency by Genome Sequencing Analysis

“…Of note, in a routine setting, QF-PCR experiment was conducted prior to CMA for the detection of MCC and common aneuploidy. However, the missed detection of decreased copy ratio of the Y chromosome by QF-PCR in this case might be due to the low-level mosaicism presented (Shin et al, 2016). In addition, GS was able to delineate the 16p11.2 recurrent deletion, which included the disease-causing gene TBX6 , the missed detection of which in this customized CMA platform was owing to the lack of probes located in the target region ( Figure 4B ).…”

Comprehensive phenotyping of fetuses with trisomy 18: a perinatal center experience

“…A study by Pan et al, 2016 reports 175 pregnancies with fetal nuchal translucency of more than 3.5 mm at 11-13 weeks of gestation and QF-PCR detected chromosomal anomalies in 30% of them including trisomy 18 in seven cases (4%) (Pan et al, 2016). Several studies support that QF-PCR can be used as a standalone procedure for targeted rapid aneuploidy diagnosis (Lildballe et al, 2014;Muthuswamy et al, 2015;Shin et al, 2016;Huo et al, 2019;Cottino et al, 2022). QF-PCR determined trisomy 18 in 6 (37%) fetuses in our perinatal cohort.…”